Answer:
(21, 3 )
Explanation:
9x = 177 + 4y ( subtract 4y from both sides )
9x - 4y = 177 → (1)
6x - 5y = 111 → (2)
multiplying (1) by 5 and (2) by - 4 and adding will eliminate y
45x - 20y = 885 → (3)
- 24x + 20y = - 444 → (4)
add (3) and (4) term by term to eliminate y
(45x - 24x) + (- 20y + 20y) = 885 - 444
21x + 0 = 441
21x = 441 ( divide both sides by 21 )
x = 21
substitute x = 21 into either of the 2 equations and solve for y
substituting into (1)
9(21) - 4y = 177
189 - 4y = 177 ( subtract 189 from both sides )
- 4y = - 12 ( divide both sides by - 4 )
y = 3
solution is (21, 3 )